selftest: size: Add size test for Linux kernel

TARGETS += sysctl

TARGETS += firmware

TARGETS += ftrace

TARGETS += size

TARGETS_HOTPLUG = cpu-hotplug

TARGETS_HOTPLUG += memory-hotplug

get_size

CC = $(CROSS_COMPILE)gcc

all: get_size

get_size: get_size.c

	$(CC) -static -ffreestanding -nostartfiles -s $< -o $@

run_tests: all

	./get_size

clean:

	$(RM) get_size

/*

 * Copyright 2014 Sony Mobile Communications Inc.

 *

 * Licensed under the terms of the GNU GPL License version 2

 *

 * Selftest for runtime system size

 *

 * Prints the amount of RAM that the currently running system is using.

 *

 * This program tries to be as small as possible itself, to

 * avoid perturbing the system memory utilization with its

 * own execution.  It also attempts to have as few dependencies

 * on kernel features as possible.

 *

 * It should be statically linked, with startup libs avoided.

 * It uses no library calls, and only the following 3 syscalls:

 *   sysinfo(), write(), and _exit()

 *

 * For output, it avoids printf (which in some C libraries

 * has large external dependencies) by  implementing it's own

 * number output and print routines, and using __builtin_strlen()

 */

#include <sys/sysinfo.h>

#include <unistd.h>

#define STDOUT_FILENO 1

static int print(const char *s)

{

	return write(STDOUT_FILENO, s, __builtin_strlen(s));

}

static inline char *num_to_str(unsigned long num, char *buf, int len)

{

	unsigned int digit;

	/* put digits in buffer from back to front */

	buf += len - 1;

	*buf = 0;

	do {

		digit = num % 10;

		*(--buf) = digit + '0';

		num /= 10;

	} while (num > 0);

	return buf;

}

static int print_num(unsigned long num)

{

	char num_buf[30];

	return print(num_to_str(num, num_buf, sizeof(num_buf)));

}

static int print_k_value(const char *s, unsigned long num, unsigned long units)

{

	unsigned long long temp;

	int ccode;

	print(s);

	temp = num;

	temp = (temp * units)/1024;

	num = temp;

	ccode = print_num(num);

	print("\n");

	return ccode;

}

/* this program has no main(), as startup libraries are not used */

void _start(void)

{

	int ccode;

	struct sysinfo info;

	unsigned long used;

	print("Testing system size.\n");

	print("1..1\n");

	ccode = sysinfo(&info);

	if (ccode < 0) {

		print("not ok 1 get runtime memory use\n");

		print("# could not get sysinfo\n");

		_exit(ccode);

	}

	/* ignore cache complexities for now */

	used = info.totalram - info.freeram - info.bufferram;

	print_k_value("ok 1 get runtime memory use # size = ", used,

		info.mem_unit);

	print("# System runtime memory report (units in Kilobytes):\n");

	print_k_value("#   Total:  ", info.totalram, info.mem_unit);

	print_k_value("#   Free:   ", info.freeram, info.mem_unit);

	print_k_value("#   Buffer: ", info.bufferram, info.mem_unit);

	print_k_value("#   In use: ", used, info.mem_unit);

	_exit(0);

}